Can´t ping the defaul gateway on the switch

Hi

I have configurd IP address on s Cisco 3550 SVI and defaul-gateway. I have also configured IP address on a cisco router fastEthernet 0/1. I can ping the SVI IP address and vice versa without any issue. But I cannot ping the IP address configured on the Switch´s default-gateway.

Please help me out.

Regards
Arhajimunye